One way you can start to make this make more sense, Sean, is if you exploit the code/data duality so that the non-distributed data that you are sending out from the driver is actually paying a role more like code (or at least parameters.) What is sent from the driver to an Executer is then used (typically as seeds or parameters) to execute some procedure on the Worker node that generates the actual data on the Workers. After that, you proceed to execute in a more typical fashion with Spark using the now-instantiated distributed data.
But I don't get the sense that this meta-programming-ish style is really what the OP was aiming at. On Thu, Aug 25, 2016 at 12:39 PM, Sean Owen <so...@cloudera.com> wrote: > Without a distributed storage system, your application can only create > data on the driver and send it out to the workers, and collect data back > from the workers. You can't read or write data in a distributed way. There > are use cases for this, but pretty limited (unless you're running on 1 > machine). > > I can't really imagine a serious use of (distributed) Spark without > (distribute) storage, in a way I don't think many apps exist that don't > read/write data. > > The premise here is not just replication, but partitioning data across > compute resources. With a distributed file system, your big input exists > across a bunch of machines and you can send the work to the pieces of data. > > On Thu, Aug 25, 2016 at 7:57 PM, kant kodali <kanth...@gmail.com> wrote: > >> @Mich I understand why I would need Zookeeper. It is there for fault >> tolerance given that spark is a master-slave architecture and when a mater >> goes down zookeeper will run a leader election algorithm to elect a new >> leader however DevOps hate Zookeeper they would be much happier to go with >> etcd & consul and looks like if we mesos scheduler we should be able to >> drop Zookeeper. >> >> HDFS I am still trying to understand why I would need for spark. I >> understand the purpose of distributed file systems in general but I don't >> understand in the context of spark since many people say you can run a >> spark distributed cluster in a stand alone mode but I am not sure what are >> its pros/cons if we do it that way. In a hadoop world I understand that one >> of the reasons HDFS is there is for replication other words if we write >> some data to a HDFS it will store that block across different nodes such >> that if one of nodes goes down it can still retrieve that block from other >> nodes. In the context of spark I am not really sure because 1) I am new 2) >> Spark paper says it doesn't replicate data instead it stores the >> lineage(all the transformations) such that it can reconstruct it. >> >> >> >> >> >> >> On Thu, Aug 25, 2016 9:18 AM, Mich Talebzadeh mich.talebza...@gmail.com >> wrote: >> >>> You can use Spark on Oracle as a query tool. >>> >>> It all depends on the mode of the operation. >>> >>> If you running Spark with yarn-client/cluster then you will need yarn. >>> It comes as part of Hadoop core (HDFS, Map-reduce and Yarn). >>> >>> I have not gone and installed Yarn without installing Hadoop. >>> >>> What is the overriding reason to have the Spark on its own? >>> >>> You can use Spark in Local or Standalone mode if you do not want Hadoop >>> core. >>> >>> HTH >>> >>> Dr Mich Talebzadeh >>> >>> >>> >>> LinkedIn * >>> https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw >>> <https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* >>> >>> >>> >>> http://talebzadehmich.wordpress.com >>> >>> >>> *Disclaimer:* Use it at your own risk. Any and all responsibility for >>> any loss, damage or destruction of data or any other property which may >>> arise from relying on this email's technical content is explicitly >>> disclaimed. The author will in no case be liable for any monetary damages >>> arising from such loss, damage or destruction. >>> >>> >>> >>> On 24 August 2016 at 21:54, kant kodali <kanth...@gmail.com> wrote: >>> >>> What do I loose if I run spark without using HDFS or Zookeper ? which of >>> them is almost a must in practice? >>> >>> >>> >
